In general, a washing machine includes a casing, a water tank disposed in the casing to store wash water therein, a wash tub rotatably mounted in the water tank to store laundry therein, and a driving unit for rotating the wash tub.
A washing machine should be balanced to prevent vibration when a wash tub rotates in washing, rinsing, dehydration and drying processes. When the washing machine is driven in an imbalanced state, for example, a state in which the washing machine is tilted by external force, the casing is tilted by improper installation, or strong vibration arises due to an imbalanced laundry load, operation of the washing machine needs to be stopped to prevent damage to devices and ensure safety. Therefore, there is a need to devise a way to accurately sense operation in an imbalanced state.